Tropentag, September 16 - 18, 2026, Göttingen "Towards multi-functional agro-ecosystems promoting climate-resilient futures"

Using unmanned aerial vehicles to identify and quantify aquatic macrophytes in shallow lakes of the Amazon region

University of Hohenheim, Institute of Plant and Landscape Ecology, Germany

Abstract

Freshwater ecosystems are sensitive to environmental changes, and aquatic macrophytes play an important role in the ecological dynamics of Amazonian floodplains by regulating nutrient cycling, contributing to sediment stabilisation and providing habitat structure for diverse aquatic organisms. These plants are highly susceptible to environmental disturbances; therefore, they are considered good bioindicators of aquatic ecosystem health, functioning, and biodiversity. The importance of the aquatic macrophytes in freshwater ecosystems is linked to their spatial distribution, which depends on many environmental factors. Their spatial distribution and species composition can indicate water quality and habitat integrity. Therefore, monitoring macrophyte communities is important for enhancing our understanding of ecosystem functioning and identifying changes related to environmental disturbances. In this study, high-resolution unmanned aircraft vehicle (UAV) imagery was used to analyse and classify the spatial distribution in seven floodplain lakes from the Peruvian Amazon, four lakes located inside the Pacaya-Samiria Natural Reserve and three outside of the protected area. The use of UAVs allows for a combination of spatial ecology with landscape-scale observations, offering a powerful tool for capturing fine-scale heterogeneity in dynamic floodplain systems. The study further compares protected and non-protected lakes to assess whether conservation status influences spatial habitat complexity and biodiversity patterns. High-resolution UAV imagery is used to map aquatic vegetation and derive spatial metrics describing habitat structure. We hypothesise that higher spatial heterogeneity is associated with higher macrophyte diversity and that protected lakes exhibit stronger structure–diversity relationships due to reduced anthropogenic disturbance and management plans in the area. Our findings highlight the potential of UAVs to support ecological research and biodiversity assessments in tropical aquatic environments, with implications for long-term ecosystem monitoring and management.

Keywords: Amazon floodplains, random forest, remote sensing, unmanned aerial vehicle

Contact Address: Gabriella Vives Rivero, University of Hohenheim, Institute of Plant and Landscape Ecology, Steigstrasse 3, 73760 Ostfildern, Germany, e-mail: gabriella.vivesuni-hohenheim.de